What is 4680 battery?
The 4680 battery is a cylindrical lithium battery with a diameter of 46 mm and a height of 80 mm. It was first designed by Tesla for commercial electric cars(Model Y). On the other hand, the volume of the 4680 cells is 5.7 times that of a 2170 lithium battery. The biggest advantage of the new Tesla 4680 battery is that it can produce more battery energy capacity with less raw materials in general. As can be seen, the total battery cost may be reduced to half cost of the 21700 battery with the gradual expansion of mass production.
Difference between tesla 4680 battery Vs 2170 battery
Just as below picture, the size of the 4680 battery is 68 in diameter and 80mm in height,However,The size of the 2170 battery is 21 in diameter and 70mm in height.
The capacity of 4680 battery is 26000mAh. but the 2170 battery only have 4800mah, that means the capacity of 4680 battery are large than 2170 battery typically.
The positive and negative poles of the 4680 battery use all-pole tabs, which means that the all-pole tabs will greatly increase the current path and make it easier for electrons to move inside the electrons. That cause the internal resistance of the 4680 battery is only one-fifth of that of the 2170 battery. Therefore, the estimated charging rate of the 4680 battery is faster than that of the 2170 battery.
According to the actual test report, it only takes 20 minutes to charge the 400 V 4680 battery system to 60%. In the future, if the 4680 battery adopts an 800 V voltage system, the charging speed will be faster.
Internal negative electrode
As we all know,the 2170 battery uses graphite as the negative electrode, but the latest 4680 battery uses silicon-based graphite as the negative electrode. Therefore, the energy density of the 4680 battery is greater than that of the 2170 battery.
Benefits of tesla 4680 battery
Faster charging speed
Since the all-pole tabs structure, we only takes 20 minutes to charge the 400 V 4680 battery system to 60%. In the future, if the 4680 battery adopts an 800 V voltage system, the charging speed will be faster.
Because the mechanical strength of the 4680 battery is higher, it is more suitable for CTC technology (Cell to Chassis). As shown in the picture below, Tesla has eliminated the battery cover on the 4680 battery array, increasing space utilization. In terms of manufacturing costs, Musk said that after adopting the CTC+ integrated die-casting technology, 370 parts can be saved, the body weight can be reduced by 10%, and the battery cost per kWh can be reduced by 7%.
Longer driven distance
As we mentioned above, the body weight are lighter 10% around since the CTC technology, that means the car can last longer when consuming the same electricity
Why Tesla change the Model Y battery from 21700 Battery to 4680 battery?
As mentioned above, Tesla is replacing 4680 batteries with 2170 batteries due to the advantages of high capacity and fast charging. Obviously, 4680 batteries have greater potential in terms of energy density, fast charging rate, cruising range, and assembly methods. . In addition, CTC technology also reduces the cost a lot. This is also the main reason why Tesla will use 4680 batteries to replace 2170 batteries.
Video explaination between tesla 4680 battery Vs 2170 battery
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